Catalyst component for polymerization of olefins

ABSTRACT

A catalyst component for polymerization of olefins which is prepared by reacting a magnesium alkoxide with a silicon compound having at least one hydrogen-silicon bond, contacting the reaction product with a carboxylic acid halide and/or carboxylic acid anhydride, and contacting the resulting contact product with a titanium compound.

Description of the Invention

1. Field of Technology:

The present invention relates to a catalyst component for polymerization of olefins. More particularly, the invention relates to (a) a catalyst component which provides olefin polymers having a high stereoregularity and a high bulk density in high yields, (b) an olefin polymerization catalyst system comprising the titanium halide containing catalyst component and an organo metal cocatalyst, and (c) the process for polymerizing olefins in the presence of the catalyst system.

2. Background Technology:

Heretofore, it has been known that a contact product of a halogen-free magnesium compound and a titanium compound is useful as a catalyst component for the polymerization of olefins. It is, however, low in catalytic performance, and attempts have been made for improvement. Such attempts include a process in which Mg(OR)₂ is contacted with titanium tetrahalide in the presence of a halogenated silane represented by SiX_(p) R_(4-p) (X=halogen, R=hydrocarbyl radical) or in the presence of said halogenated silane and an electron donor compound (Japanese Patent Laid-open No. 98076/1977), a process in which a magnesium compound having the Mg--O--R linkage is contacted with a halogenating agent such as a silicon compound represented by the formula X_(m) SiR_(n) (X and R being as defined above) in the presence of an electron donor compound (Japanese Patent Laid-open No. 43094/1978), a process in which the solid reaction product of a halogenated aluminum, an organic compound having the Si--O bond, and magnesium alcoholate is contacted with a tetravalent titanium compound having at least one halogen atom U.S. Pat. No. 4,242,479, a process in which the reaction product of a magnesium compound, titanium compound, and silicon compound is contacted with at least one kind of halogenated aluminum compound (Japanese Pat. Laid-open No. 155205/1981).

The catalyst components obtained according to the above-mentioned processes, however, are poor in catalytic activity and stereoregularity and provide polymers having a low bulk density. In addition to the above-mentioned catalyst components, there is known one which is obtained by contacting a magnesium compound, an electron donor compound, a silicon compound having the Si--H bond, and a titanium halide compound all together (Japanese Patent Laid-open No. 92009/1982). According to this process, the magnesium compound is essentially a magnesium halide and the silicon compound and titanium halide are used simultaneously for contacting. Therefore, the resulting product is not necessarily satisfactory.

SUMMARY OF THE INVENTION

In order to produce from a halogen-free magnesium compound a catalyst component which can be made into a catalyst which exhibits high stereoregularity and high catalytic activity and provides olefin polymers having a high bulk density, the present inventors carried out extensive researches, which led to the findings that the object can be achieved with a solid substance obtained by reacting a magnesium hydrocarbyl oxide with a silicon compound having the hydrogen-silicon bond, contacting the reaction product with a carboxylic acid halide and/or carboxylic acid anhydride, and contacting the resulting contact product with a titanium compound. The present invention has been completed based on these findings.

The essence of this invention resides in a catalyst component for polymerization of olefins which is prepared by reacting a magnesium hydrocarbyl oxide with a silicon compound having the hydrogen-silicon bond, contacting the reaction product with a carboxylic acid halide and/or carboxylic acid anhydride, and contacting the resulting contact product with a titanium compound.

Raw Materials for Catalyst Component

The raw materials used for preparing the catalyst component of this invention are described below.

(A) Magnesium Hydrocarbyl Oxide

The magnesium hydrocarbyl oxide used in this invention is represented by the formula Mg(OR)(OR'), wherein R and R' are alkyl, alkenyl, cycloalkyl, aryl, or aralkyl groups having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, and R and R" may be the same or different.

These compounds include, for example, Mg(OCH₃)₂, Mg(OC₂ H₅)₂, Mg(OCH₃)(OC₂ H₅), Mg(Oi-C₃ H₇)₂, Mg(OC₃ H₇)₂, Mg(OCH₄ H₉)₂, Mg(Oi-C₄ H₉)₂, Mg(OC₄ H₉)(O-iC₄ H₉), Mg(OC₄ H₉)(Osec-C₄ H₉), Mg(OC₆ H₁₃)₂, Mg(OC₈ H₁₇)₂, Mg(OC₆ H₁₁)₂, Mg(OC₆ H₅)₂, Mg(OC₆ H₄ CH₃)₂, and Mg(OCH₂ C₆ H₅)₂.

These magnesium hydrocarbyl oxides should preferably be dried before use, and more preferably be dried with heating under reduced pressure. These magnesium hydrocarbyl oxides may be obtained commercially or may be synthesized according to the known methods.

These magnesium hydrocarbyl oxides may be contacted with an inorganic or organic inert solid substance prior to use.

Suitable inorganic solid substances include metal compounds in the form of sulfate, hydroxide, carbonate, phosphate, or silicate. Examples of such compounds include Mg(OH)₂, BaCO₃, and Ca₃ (PO₄)₂.

Suitable organic solid substances include low-molecular aromatic hydrocarbons such as durene, anthracene, napthalene, and diphenyl. They also include high-molecular compounds such as polyethylene, polypropylene, polyvinyl toluene, polystyrene, polymethyl methacrylate, polyamide, polyester, and polyvinyl chloride.

(B) Silicon Compound

The silicon compound used in this invention may be any compound having the hydrogen-silicon bond. It is represented by the formula H_(m) R_(n) SiX_(r), wherein R is (1) a hydrocarbon group, (2) R'O(R' is a hydrocarbon group), (3) R² R³ N-- (R² and R³ are hydrocarbon groups), or (4) R⁴ COO-- (R⁴ is a hydrogen atom or hydrocarbon group); X is a halogen atom; and m is 1 to 3, 0≦r<4, and m+n+r=4. When n is greater than 1, R may be the same or different.

The hydrocarbon groups represented by R, R¹, R², R³, and R⁴ include alkyl, alkenyl, cycloalkyl, aryl, and aralkyl groups of carbon number 1 to 16. The alkyl group includes, for example, methyl, ethyl, propyl, n-butyl, isobutyl, n-hexyl, n-octyl, 2-ethylhexyl, and n-decyl. The alkenyl group includes, for example, vinyl, allyl, isopropenyl, propenyl, and butenyl. The cycloalkyl group includes, for example, cyclopentyl and cyclohexyl. The aryl group includes, for example, phenyl, tolyl, and xylyl. The aralkyl group includes, for example, benzyl, phenetyl, and phenylpropyl.

Preferable among them are lower alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, and t-butyl, and aryl groups such as phenyl and tolyl.

X denotes halogen atoms such as chlorine, bromine, and iodine. The preferred halogen is chlorine.

The silicon compounds are exemplified by HSiCl₃, H₂, SiCl₂, H₃ SiCl, HCH₃ SiCl₂, HC₂ H₅ SiCl₂, H(t-C₄ H₉)SiCl₂, HC₆ H₅ SiCl₂, H(CH₃)₂ SiCl, H(i-C₃ H₇)₂ SiCl, H₂ C₂ H₃ SiCl, H₂ (n-C₄ H₉)SiCl, H₂ (C₆ H₄ CH₃)SiCl, HSi(CH₃)₃, HSiCH₃ (OCH₃)₂, HSiCH₃ (OC₂ H₅)₂, HSI (OCH₃)₃, (C₂ H₅)₂ SiH₂, HSI (CH₃)₂ (OC₂ H₅), HSI (CH₃)₂ [N(CH₃)₂ ], HSiCH₃ (C₂ H₅)₂, HSiC₂ H₅ (OC₂ H₅)₂, HSiCH₃ [N(CH₃)₂ ]₂, C₆ H₅ SiH₃, HSI(C₂ H₅)₃, HSi(OC₂ H₅)₃, HSi(CH₃)₂ [N(C₂ H₅).sub. 2 ], C₆ H₅ CH₃ SiH₂, C₆ H₅ (CH₃)₂ SiH, (n-C₃ H₇)₃ SiH, HSiCl(C₆ H₅)hd 2, H₂ Si(C₆ H₅)₂, HSi(C₆ H₅)₂ CH₃, (n-C₅ H₁₁ O)₃ SiH, HSi(C₆ H₅)₃, and (n-C₅ H₁₁)₃ SiH. Another example of the compounds not covered by the above formula include (ClCH₂ CH₂ O)₂ -CH₃ SiH, HSi(OCH₂ CH₂ Cl)₃, [H(CH₃)₂ Si]₂ O, [H(CH₃)₂ Si]₂ NH, (CH₃)₃ SiOSi(CH₃)₂ H, [H(COH₃)₂ Si]₂ C₆ H₄ [H(CH₃)₂ SiO]₂ -Si(CH₃)₂, [(CH₃)₃ SiO]₂ SiHCH₃, [(CH₃)₃ SiO]₃ SiH, and ]Si(CH₃)(H)O]₅.

Preferable among these halogenated silicon compounds are those which are represented by the formula in which R is a hydrocarbon, n is 0 to 2, and r is 1 to 3. They are HSiCl₃, H₂ SiCl₂, H₃ SiCl, HCH₃ SiCl₂, HC₂ H₅ SiCl₂, H(t-C₄ H₉)SiCl₂, HC₆ H₅ SiCl₂, H(CH₃₂ SiCl, H(i-C₃ H₇)₂ SiCl, H₂ C₂ H₅ SiCl, H₂ (n-C₄ H₉)SiCl, H₂ (C₆ H₄ CH₃)SiCl, and HSiCl-(C₆ H₅)₂. Most preferable among them are HSiCl₃, HCH₃ SiCl ₂, and H(CH₃)₂ SiCl. Especially preferred among the silicon compounds is HSiCl₃.

(C) Carboxylic Acid Halide and Carboxylic Acid Anhydride

Examples of the carboxylic anhydride include aliphatic monocarboxylic anhydrides such as acetic anhydride, propionic anhydride, butyric anhydride, valeric anhydride, and caproic anhydride; aliphatic olefinmonocarboxylic anhydrides such as acrylic anhydride, crotonic anhydride, and methacrylic anhydride; alicyclic carboxylic anhydrides such as cyclohexanemonocarboxylic anhydride, cyclohexenemonocarboxylic anhydride, cis-1, 2-cyclohexanedicarboxylic anhydride, and cis-4-cyclohexene-1, 2-dicarboxylic anhydride; aromatic monocarboxylic anhydrides such as benzoic anhydride, p-toluylic anhydride, p-ethylbenzoic anhydride, and p-methoxybenzoic anhydride; and aromatic dicarboxylic anhydrides such as phthalic anhydride. Preferable among them are aromatic carboxylic anhydrides, and especially benzoic anhydride.

Examples of the carboxylic acid halides includes aliphatic monocarboxylic acid halides such as acetyl chloride, propionyl chloride, and n-butylyl chloride; and acid bromides such as acetyl bromide and n-butylyl bromide; and acid iodides such as acetyl iodide and n-butylyl iodide, aliphatic monoolefincarboxylic acid halides such as acryl chloride, crotonyl chloride, and methacryl chloride; acid bromides such as acryl bromide and methacryl bromide; and acid iodides such as acryl iodide and methacryl iodide, alicyclic carboxylic acid halides such as cyclohexanecarboxylic acid chloride, cis-4-methylcyclohexanecarboxylic acid chloride, 1-cyclohexenecarboxylic acid chloride, cyclohexanecarboxylic acid bromide, and cis-4-methylhexenecarboxylic acid bromide, aromatic monocarboxylic acid halides such as benzoyl chloride, p-toluic acid chloride, p-ethylbenzoic acid chloride, and p-methoxybenzoic acid chloride; acid bromides such as benzoyl bromide; and acid iodides such as benzoyl iodide, and aromatic dicarboxylic acid halides such as phthalic acid dichloride. Preferable among them are aromatic carboxylic acid halides and especially benzoyl chloride.

(D) Titanium Compound

The titanium compound used in this invention includes divalent, trivalent, and tetravalent titanium compounds. They are exemplified by titanium tetrachloride, titanium tetrabromide, trichloroethoxytitanium, trichlorobutoxytitanium, dichlorodibutoxytitanium, dichlorodiethoxytitanium, dichlorodiphenoxytitanium, chlorotiethoxytitanium, chlorotributoxytitaniumn, tetrabotoxytitanium, and titanium trichloride. Preferable among them are tetravalent titanium halides such as titanium tetrachloride, trichloroethoxytitanium, dichlorodibutoxytitanium, and dichlorodiphenoxytitanium, and most preferable is titanium tetrachloride.

Preparation of Catalyst Component

The catalyst component of this invention is prepared by reacting a magnesium hydrocarbyl oxide (component A) with the silicon compound containing at least one H-Si bond (component B), contacting the reaction product with a carboxylic acid halide and/or carboxylic acid anhydride (component C) (referred to as carboxylic acid derivatives), and contacting the resulting contact product with a titanium compound (component D). The process is described below.

(1) Reaction of Magnesium Alkoxide with Silicon Compound

The reaction of a magnesium hydrocarbyl oxide (component A) with the silicon compound containing at least one H-Si bond (component B) is accomplished by contacting the two components with each other. The contacting can be accomplished by mixing/stirring or mechanically copulverizing the two compounds in the presence or absence of a hydrocarbon. Preferably, the two components should be mixed and stirred in a hydrocarbon.

The Preferred hydrocarbon is a saturated aliphatic, saturated alicyclic, or aromatic hydrocarbon of carbon number 6 to 12 such as hexane, heptane, octane, cyclohexane, benzene, toluene, and xylene.

One mol of component A is contacted with 0.5 to 10 mol, preferably 1 to 5 mol of component B. Usually, the contacting is performed at 0° to 200° C. for 0.5 to 100 hours. More than one kind each of component A and component B may be used.

The hydrocarbon may be used in any amount; but it should preferably be less than 100 ml for 1 g of component A.

In the case where a halogenated silicon compound is used as component B, a gas is formed when component A is contacted with component B. This indicates that the reaction is taking place. The quantity of silicon atom in the reaction product, which is insoluble in an inert solvent, particularly n-hexane or n-heptane, at 65° C., is more than 8 wt %.

The contact product of component A and component B is separated from the reaction system, and is used for the subsequent contacting. If necessary, it may be washed with an inert hydrocarbon such as one which is used in the contacting of component A and component B, prior to the subsequent contacting. This washing may be carried out with heating.

(2) Contacting with Carboxylic Acid Derivative

The contacting of the reaction product obtained in the above step (1) with a carboxylic acid derivative (component C) may be accomplished by mixing and stirring them together in the presence or absence of an inert hydrocarbon, or by mechanically copulverizing them. The inert hydrocarbon includes hexane, heptane, octane, cyclohexane, benzene, toluene, and xylene.

The contacting by mechanical copulverization should be carried out at 0° to 100° C. for 0.1 to 100 hours. The contacting by mere stirring should be carried out at 0° to 150° C. for 0.5 to 10 hours.

Component C is used in an amount of 0.01 to 10 gram mol, particularly 0.05 to 1 gram mol, for 1 gram atom of magnesium in the reaction product of magnesium alkoxide and silicon compound.

(3) Contacting with Titanium Compound

The contact product obtained in the above step (2) is then contacted with a titanium compound (component D). Prior to contacting with component D, the contact product may be washed with a proper cleaning agent such as the above-mentioned hydrocarbon.

The two components may be contacted with each other as such; but it is preferable that they are mixed and stirred in a hydrocarbon. The hydrocarbon includes hexane, heptane, octane, cyclohexane, benzene, toluene, and xylene.

Component D is used in an amount more than 0.1 gram mol, particularly 1 to 50 gram mol, for 1 gram atom of magnesium in the contact product.

The contacting should be carried out at 0° to 200° C. for 0.5 to 20 hours, and preferably at 60° to 150° C. for 1 to 5 hours.

The contacting with component D should preferably be carried more than once. Where the previous contacting has been carried out in a hydrocarbon, the contact product should be separated from the hydrocarbon prior to the subsequent contacting.

The solid substance obtain as mentioned above is washed, if required, with an inert hydrocarbon such as hexane, heptane, octane, cyclohexane, benzene, toluene, and xylene, followed by drying, whereby there is obtained the catalyst component of this invention.

The catalyst component of this invention is powder having a specific surface area of 50 to 650 m² /g as measured by BET method at the adsorption temperature of liquid nitrogen, a pore volume of 0.05 to 0.40 cc/g, and a narrow particle size distribution.

Catalyst for Polymerization of Olefin

The titanium-containing solid catalyst component of this invention is combined with an organoaluminum compound to provide a catalyst for homopolymerization of an olefin or for copolymerization of an olefin and other olefin.

Organoaluminum Compound

The organoaluminum compound to be combined with the catalyst component is one which is represented by the formula R_(n) AlX_(3-n), wherein R is an alkyl group or aryl group, X is a halogen atom, alkoxy group, or hydrogen atom, n is an arbitrary number in the range of 1≦n<3. Preferred ones are alkyl aluminum compounds and a mixture thereof or complex thereof having 1 to 18 carbon atoms, preferably 2 to 6 carbon atoms, such as trialkyl aluminum, dialkyl aluminum monohalide, monoalkyl aluminum dihalide, alkyl aluminum sesquihalide, dialkyl aluminum monoalkoxide, and dialkyl aluminum monohydride. Examples of such compounds include trialkyl aluminum such as trimethyl aluminum, triethyl aluminum, tripropyl aluminum, triisobutyl aluminum, and trihexyl aluminum; dialkyl aluminum monohalide such as dimethyl aluminum chloride, diethyl aluminum chloride, diethyl aluminum bromide, diethyl aluminum iodide, and diisobutyl aluminum chloride; monoalkyl aluminum dihalide such as methyl aluminum dichloride, ethyl aluminum dichloride, methyl aluminum dibromide, ethyl aluminum dibromide, ethyl aluminum diiodide, and isobutyl aluminum dichloride; alkyl aluminum sesquihalide such as ethyl aluminum sesquichloride; dialkyl aluminum monoalkoxide such as dimethyl aluminum methoxide, diethyl aluminum ethoxide, diethyl aluminum phenoxide, dipropyl aluminum ethoxide, diisobutyl aluminum ethoxide, and diisobutyl aluminum phenoxide; and dialkyl aluminum hydride such as dimethyl aluminum hydride, diethyl aluminum hydride, dipropyl aluminum hydride, and diisobutyl aluminum hydride.

Preferable among them is trialkyl aluminum, particularly triethyl aluminum and triisobutyl aluminum. The trialkyl aluminum can be used in combination with the other organoaluminum compound such as commercially available diethyl aluminum chloride, ethyl aluminum dichloride, ethyl aluminum sesquichloride, diethyl aluminum ethoxide, and diethyl aluminum hydride, and a mixture or complex thereof.

In addition, the organoaluminum compound may be used alone or in combination with an electron donor compound. Preferable ones are carboxylic acids, carboxylic esters, alcohols, ethers, ketones, amines, amides nitriles, aldehydes, alcoholates, phosphoamides, thioethers, thioesters, and carbonic esters, and phosphorus, arsenic, and antimony compounds in which these atoms are bonded to an organic group through a carbon or oxygen. Preferable among them are carboxylic esters, alcohols, and ethers.

Examples of carboxylic esters include butyl formate, ethyl acetate, butyl acetate, ethyl acrylate, ethyl butyrate, isobutyl isobutyrate, methyl methacrylate, diethyl maleate, diethyl tartrate, ethyl cyclohexanecarbonate, ethyl benzoate, ethyl p-methoxybenzoate, methyl p-methylbenzoate, ethyl p-tert-butylbenzoate, dibutyl phthalate, diallyl phthalate, and ethyl alpha-naphthoate. They are not limitative. Preferable among them are alkyl esters of aromatic carboxylic acid, particularly C₁₋₈ alkyl esters of benzoic acid or nucleus-substituted benzoic acid such as p-methylbenzoic acid and p-methoxy benzoic acid.

The alcohols are represented by the formula ROH, wherein R is an alkyl, alkenyl, cycloalkyl, aryl, or aralkyl group of carbon number 1 to 12. Examples of the alcohols include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol, hexanol, octanol, 2-ethylhexanol, cyclohexanol, benzyl alcohol, and allyl alcohol.

The ethers are represented by the formula ROR', wherein R and R' are alkyl, alkenyl, cycloalkyl, aryl, or aralkyl groups of carbon number 1 to 12, and R and R' may be the same or different. Examples of the ethers include diethyl ether, diisopropyl ether, dibutyl ether, diisobutyl ether, diisoamyl ether, di-2-ethylhexyl ether, diallyl ether, ethyl allyl ether, butyl allyl ether, diphenyl ether, anisole, and ethyl phenyl ether.

The electron donor compound may be used when an organoaluminum compound is used in combination with the catalyst component, or may be used after being contacted with an organoaluminum beforehand.

The organoaluminum compound is used in an amount of 1 to 2000 gram mol, preferably 20 to 500 gram mol, for 1 gram atom of titanium in the catalyst component.

The ratio of the organoaluminum compound to the electron donor compound is such that aluminum in the organoaluminum compound is 0.1 to 40 gram atom, preferably 1 to 25 gram atom, for 1 mol of the electron donor compound.

Polymerization of Olefin

The catalyst composed of the catalyst component prepared as mentioned above and an organoaluminum compound (and an electron donor compound) is useful as a catalyst for homopolymerization of monoolefin or copolymerization of monoolefin and other monoolefin or diolefin. It exhibits outstanding performance as a catalyst for homopolymerization of an alpha-olefin of carbon number 3 to 6, such as propylene, 1-butene, 4-methyl-1-pentene, and 1-hexene, or random or block copolymerization of the above-mentioned alpha-olefins with one another or with ethylene; and for homopolymerization of ethylene or random or block copolymerization of ethylene with an alpha-olefin of carbon number 3 to 10, such as propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene.

The polymerization may be performed either in gas phase or liquid phase. The liquid phase polymerization may be accomplished in an inert hydrocarbon such as n-butane, isobutane, n-pentane, isopentane, hexane, heptane, octane, cyclohexane, benzene, toluene, and xylene, or in the liquid monomer. The polymerization temperature is usually -80° C. to +150° C., preferably 40° C. to 120° C. The polymerization pressure is 1 to 60 atm. The molecular weight modification of the resulting polymer is accomplished in the presence of hydrogen or other known molecular weight modifiers. In the copolymerization of olefin, the quantity of other olefin to be copolymerized is usually less than 30 wt %, particularly 0.5 to 15 wt %, based on the olefin. The polymerization with the catalyst system of this invention may be performed continuously or batchwise under the commonly used conditions. The copolymerization may be accomplished in one step or in two or more steps.

Effect of Invention

The catalyst component of this invention is useful for the production of polyolefins, particularly isotactic polypropylene, ethylene-propylene random copolymer, and ethylene-propylene block copolymer.

The polymerization catalyst made from the catalyst component of this invention exhibits a high catalytic activity and stereoregularities and keeps it high activity for a long time. It provides polymer powder having a high bulk density and flowability.

EXAMPLES

The invention is described in more detail with reference to the following examples and application examples. The scope of this invention is not limited by these examples. Percent (%) in the examples and application examples means wt %, unless otherwise indicated.

The specific surface area (S.A.) and pore volume (P.V.) of the catalyst component were measured by using SORPTOMATIC, Model 1810, made by CARLO ERBA.

The catalytic activity Kc is the quantity (g) of polymer formed per 1 g of catalyst, and Kt is the quantity (kg) of polymer formed per 1 g of titanium in the catalyst.

The heptane insoluble (referred to as HI hereinafter) which indicates the ratio of crystalline fractions in the polymer is the quantity of residues which remain after extraction for 6 hours with boiling n-heptane in a Soxhlet apparatus of improved type.

The melt flow rate (MFR) and melt index (MI) were measured according to ASTM-D1238. The bulk density was measured according to ASTM-D1895-69, Method A.

EXAMPLE 1 Contacting of Magnesium Diethoxide with Trichlorosilane

Into a 2-liter glass reactor equipped with a reflux condenser, dropping funnel, and stirrer and replaced with nitrogen were charged 120 g (1.05 mol) of commercial magnesium diethoxide and 680 ml of n-heptane. With stirring at room temperature, a mixture of 356 g (2.63 mol) of trichlorosilane and 250 ml of n-heptane was added dropwise from the dropping funnel over 45 minutes. Stirring was continued for 6 hours at 70° C. During the reaction, a gas composed mainly of ethylene and ethyl chloride formed. The resulting solids were filtered off at 70° C. and then washed by stirring in 600 ml of n-hexane at 65° C. for 10 minutes. The supernatant liquid was removed by decantation. Washing with n-hexane was repeated 4 times, and the solids were dried at 60° C. for 1 hour under reduced pressure. Thus there was obtained 164 g of solid component (I). This solid component was found to contain 13.0% of magnesium, 13.8% of silicon, and 47.8% of chlorine, and to have a specific surface area of 31 m² /g and a pore volume of 0.08 cc/g.

Contacting with Benzoyl Chloride

18 g of the solid component (I) was placed in a 300-ml stainless steel (SUS316) mill pot containing 100 pieces of stainless steel (SUS316) balls, 12 mm in diameter, under the nitrogen atmosphere. Then 4.5 g of benzoyl chloride was added to the mill pot. The mill pot was mounted on a shaker and shaken for 1 hour for crushing. Thus there was obtained a solid component (II).

Contacting with Titanium Tetrachloride

7 g of the solid component (II) was placed in a 200-ml glass reactor equipped with a stirrer under the nitrogen atmosphere. Then 40 ml of toluene and 60 ml of titanium tetrachloride were added, followed by stirring at 90° C. for 2 hours. The resulting solid substance was filtered off at 90° C. After washing 7 times with 90 ml portions of n-hexane at room temperature, the solids were dried at room temperature for 1 hour under reduced pressure. Thus there was obtained 5.1 g of catalyst component containing 3.0% of titanium, 17.3% of magnesium, 57.2% of chlorine, and 3.9% of silicon. The catalyst component was found to have a specific surface area of 280 m² /g and a pore volume of 0.23 cc/g.

EXAMPLE 2

A catalyst component was prepared in the same way as in Example 1, except that benzoyl chloride was replaced by benzoic anhydride. Table 1 shows the composition of the resulting catalyst component.

EXAMPLE 3

7 g of the solid component (II) obtained in Example 1 was placed in a 200-ml glass reactor equipped with a stirrer under the nitrogen atmosphere. Then 40 ml of toluene and 60 ml of titanium tetrachloride were added, followed by stirring at 90° C. for 2 hours. The supernatant liquid was removed by decantation. After washing four times with 90 ml portions of toluene at 60° C., 40 ml of toluene and 60 ml of titanium tetrachloride were added, followed by stirring at 90° C. for 2 hours. The resulting solid substance was filtered off at 90° C. After washing 7 times with 90 ml portions of n-hexane at room temperature, the solids were dried at room temperature for 1 hour under reduced pressure. Thus there was obtained a catalyst component having the composition as shown in Table 1.

EXAMPLES 4 to 6

Solid component (II) was prepared in the same way as in Example 1, except that benzoyl chloride was replaced by p-toluylic acid chloride (Example 4), benzoic anhydride (Example 5), and phthalic anhydride (Example 6). The solid component (II) was contacted with titanium tetrachloride twice in the same was as in Example 3 to give catalyst components. Table 1 shows the compositions of the resulting catalyst components.

EXAMPLE 7

Solid component (II) was prepared in the same way as in Example 1, except that trichlorosilane used for the contacting of magnesium diethoxide was replaced by methyldichlorosilane.

The solid component (II) was contacted with titanium tetrachloride twice in the same way as in Example 3 to give a catalyst component. Table 1 shows the composition of the resulting catalyst component.

EXAMPLE 8

Solid component (II) was prepared in the same way as in Example 1, except that trichlorosilane was replaced by methyldichlorosilane and benzoyl chloride was replaced by benzoic anhydride.

The solid component (II) was contacted with titanium tetrachloride twice in the same way as in Example 3 to give a catalyst component having the composition as shown in Table 1.

EXAMPLE 9

8.3 g of the solid component (I) obtained in Example 1 was placed in a 200-ml glass reactor equipped with a stirrer under the nitrogen atmosphere. Then 80 ml of heptane was added to make slurry. Then, 3.7 g of benzoyl chloride was added, followed by reaction at 70° C. for 2 hours. The resulting solid substance was filtered off at 70° C. and washed five times with 90 ml portions of n-hexane at 60° C.

This solid substance was contacted with titanium tetrachloride in the same way as in Example 3 to give a catalyst component having the composition as shown in Table 1.

EXAMPLE 10

A catalyst component was prepared in the same way as in Example 9, except that benzoyl chloride was replaced by benzoic anhydride. Table 1 shows the composition of the resulting catalyst component.

Comparative Example 1

Into the same mill pot as used in Example 1 were charged under the nitrogen atmosphere 31.5 g of commercial magnesium diethoxide and 10.0 g of benzoic anhydride. The mill pot was shaken on a shaker for 15 hours.

5.0 g of the resulting ground solid was placed in a 500-ml glass container equipped with a stirrer, and 300 ml of n-heptane was added. Then 9 ml of titanium tetrachloride was added dropwise over 15 minutes at room temperature. Further, 35 ml of trichlorosilane was added dropwise in the same way, followed by stirring at 90° C. for 2 hours.

The resulting solid substance was filtered off at 90° C. and washed 6 times with 150 ml portions of n-hexane at room temperature. The solid substance was dried at room temperature for 1 hour under reduced pressure. Table 1 shows the compositions of the resulting catalyst component.

COMPARATIVE EXAMPLE 2

Comparative Example 1 was repeated, except that benzoic anhydride was replaced by 7.5 ml of ethyl benzoate. Table 1 shows the composition of the resulting catalyst component.

                  TABLE 1                                                          ______________________________________                                                Silicon Compound-                                                              treated Solid                                                                               Catalyst Component                                                Composition (%)                                                                             Composition (%)                                                   Mg   Si      Cl      Mg    Ti   Si   Cl                                 ______________________________________                                         Example                                                                        1        13.0   13.8    47.8  17.3  3.0  3.9  57.2                             2        13.0   13.8    47.8  16.9  4.3  3.3  58.5                             3        13.0   13.8    47.8  17.8  4.1  2.9  56.9                             4        13.0   13.8    47.8  17.2  3.8  2.7  57.4                             5        13.0   13.8    47.8  16.8  3.7  2.9  57.1                             6        13.0   13.8    47.8  17.5  4.0  3.2  56.9                             7        12.8   14.2    48.3  17.1  4.2  3.2  58.5                             8        12.8   14.2    48.3  17.4  4.3  3.3  57.9                             9        13.0   13.8    47.8  16.8  3.8  2.5  58.3                             10       13.0   13.8    47.8  17.3  3.9  2.8  58.1                             Comparative                                                                    Example                                                                        1        --     --      --    15.2  5.3  0.6  44.1                             2        --     --      --    14.3  5.9  0.6  42.6                             ______________________________________                                    

APPLICATION EXAMPLE 1 Polymerization of Propylene

20.1 mg of catalyst component obtained in Examples 1, 3.15 ml of triethyl aluminum (abbreviated as TEAL hereinafter) solution in n-heptane, and 0.17 ml of ethyl p-methoxybenzoate were mixed. After standing for 5 minutes, the mixture was added to a 1.5-liter stainless steel (SUS 32) autoclave equipped with a stirrer under the nitrogen atmosphere. (The n-heptane solution of TEAL contains 1 mol of TEAL in 1 liter of n-heptane, and 3.15 ml of the solution corresponds to 250 gram atom of aluminum for 1 gram atom of titanium in the catalyst component. 0.17 ml of ethyl p-methoxybenzoate corresponds to 0.33 mol for 1 gram atom of aluminum in TEAL.) Then, 0.6 liter of hydrogen as the molecular weight modifier and 0.8 liter of liquefied propylene were forced into the autoclave. The reaction system was heated to 70° C., and the polymerization of propylene was carried out for 1 hour. After the polymerization was complete, unreacted propylene was purged. Thus there was obtained 191.0 g of white polypropylene powder having an HI of 93.8% (heptane insolubles indicating the crystalline fraction in the polymer), an MFR of 4.2 (melt flow rate), and a bulk density of 0.36 g/cm³. Kc=9,500 [quantity (g) of polymer formed per 1 g of catalyst] Kt=317 [quantity (kg) of polymer formed per 1 g of Ti in the catalyst]

APPLICATION EXAMPLES 2 to 12

Polymerization of propylene was carried out in the same way as in Application Example 1, except that the catalyst component obtained in Example 1 was replaced by those which were obtained in Examples 2 to 10 and Comparative Examples 1 and 2. The results are shown in Table 2.

                  TABLE 2                                                          ______________________________________                                         Applica-                            MFR   Bulk                                 tion   Catalyst   Kc      Kt   HI   (g/10 density                              Example                                                                               Component  (g)     (kg) (%)  min)  (g/cm.sup.3)                         ______________________________________                                         1      Example 1   9,500  317  93.8 4.2   0.36                                 2      Example 2   9,700  294  94.0 4.3   0.37                                 3      Example 3  11,500  397  94.5 3.8   0.37                                 4      Example 4  10,100  374  94.2 3.9   0.38                                 5      Example 5  12,100  417  94.8 3.5   0.37                                 6      Example 6   9,500  297  93.9 4.3   0.38                                 7      Example 7  10,600  331  94.5 3.6   0.38                                 8      Example 8  11,400  345  94.7 3.2   0.38                                 9      Example 9  11,300  452  94.7 3.5   0.37                                 10     Example 10 12,500  446  95.0 3.0   0.38                                 11     Comparative                                                                                 480    9   86.7 --    --                                          Example 1                                                               12     Comparative                                                                                 600    10  85.1 --    --                                          Example 2                                                               ______________________________________                                     

What is claimed is:
 1. A catalyst component for the polymerizatin of olefins obtained by reacting (A) Mg(OR)(OR'), (B) a silicon compound having at least one silicon-hydrogen bond, contacting the reaction product with (C) a carboxylic acid halide, a carboxylic acid anhydride, or mixtures thereof, and contacting the resulting contact product with a divalent, trivalent, or tetravalent titanium compound selected from titanium halides, alkoxy titanium compounds and haloalkoxy titanium compounds, when R and R' are radicals selected from alkyl, alkenyl, cycloalkyl, aryl, and aralkyl radicals and R and R' may be the same or different.
 2. The catalyst component of claim 1 wherein the titanium compound is tetravalent.
 3. The catalyst component of claim 2 wherein the titanium compound is titanium tetrachloride.
 4. The catalyst component of claim 1 wherein R and R' are alkyl radicals having from 1 to 8 carbon atoms, the silicon compound is trichlorosilane, and the carboxylic acid derivative is selected from benzoyl chloride and benzoic anhydride.
 5. The catalyst component of claim 4 wherein R and R' are ethyl.
 6. The catalyst component of claim 1 wherein the catalyst component is recovered and prior to washing, contacted at least an additional time with the titanium compound.
 7. A catalyst system for the polymerization of olefins comprising the catalyst component of claim 1 and an organoaluminum cocatalyst.
 8. A catalyst system for the polymerization of olefins comprising the catalyst component of claim 2 and an organoaluminum cocatalyst.
 9. A catalyst system for the polymerization of olefins comprising the catalyst component of claim 3 and an organoaluminum cocatalyst.
 10. A catalyst system for the polymerization of alpha-olefins comprising the catalyst component of claim 4 and an organoaluminum cocatalyst.
 11. A catalyst system for the polymerization of alpha-olefins comprising the catalyst component of claim 5 and an organoaluminum cocatalyst.
 12. A catalyst system for the polymerization of alpha-olefins comprising the catalyst component of claim 6 and an organoaluminum cocatalyst.
 13. A catalyst component for the polymerization of olefins obtained(1) reacting (A) magesium diethoxide with (B) trichlorosilane, (2) contacting the reaction product with (C) benzoylchloride or benzoic anhydride or mixture thereof, and (3) contacting the resulting contact product with (D) titanium tetrachloride.
 14. The catalyst component of claim 13 wherein the reaction product is contacted with benzoylchloride.
 15. The catalyst component of claim 13 wherein the reaction product is contacted with benzoic acid.
 16. The catalyst component of claim 13 wherein the catalyst component is recovered and prior to washing, contacted at least an additional time with titanium tretrachloride.
 17. The catalyst component of claim 13 wherein in 1 mole of component (A) is reacted with 0.5 to 10 mole of component (B), component (C) is used in an amount of 0.01 to 10 g/mole for 1 g atom of magnesium in the reaction product, and component (D) is used in an amount of more than 0.1 g/mole for 1 g atom of magnesium in the reaction product.
 18. The catalyst component of claim 17 wherein component (D) is used in an amount of 1-50 g/mole to 1 g atom of magnesium in the reaction product.
 19. A catalyst system for the polymerization of olefins comprising the catalyst component of claim 13 and anorganoalumnium cocatalyst.
 20. A catalyst system for the polymerization of olefins comprising the catalyst component of claim 14 and an organoalumnium cocatalyst.
 21. A catalyst system for the polymerization of olefins comprising the catalyst component of claim 15 and an organoalumnium cocatalyst.
 22. A catalyst system for the polymerization of olefins comprising the catalyst component of claim 16 and an organoalumnium cocatalyst.
 23. A catalyst system for the polymerization of olefins comprising the catalyst component of claim 17 and an organoalumnium cocatalyst.
 24. A catalyst system for the polymerization of olefins comprising the catalyst component of claim 18 and an organoalumnium cocatalyst. 